GitHub Action workflow is not YAML!

Why aren’t GitHub Action workflows written in YAML? They are YAML-like but don’t, for example, support anchors. As a short term could the developers support this?

  • Workflow is written using YAML comlpete with anchors etc
  • YAML is read and then written out as expanded “GitHub Actions YAML”
  • From here, the existing GitHub Actions processing should be able to handle the intermediate file.

I’m not sure whether the YAML specification requires that a parser has to support all features including anchors. However, it’s fair to say that the workflow parser isn’t fully compliant. It’s still YAML syntax nonetheless, and there are many parsers in fact that aren’t fully compliant to the specification in other regards. Anyway, there’s another topic where anchor support for GitHub Actions is discussed in detail: